Tactical flexibility combined with the compact length of the 16" barrel and collapsible stock are standard to any A4 carbine model but add in the advancements that engineers have made standard on every ArmaLite AR-10, such as improved feeding, extraction and ejection, and there is not another heavy caliber carbine that can compare. The AR-10A4 Carbine offers the same sighting choices as the AR-10A4 SPR in a handy compact format. Supplied with one 10 round and one 20 round magazine.